Just a day before Apple is expected to launch a new iPhone, Google today released its first iOS YouTube app.

The move, if not the timing, was anticipated: Last month Apple confirmed that its YouTube license had ended, and that its own app -- included with every iPhone since the device's 2007 debut -- would not appear in iOS 6, the upgrade Apple will issue later this month.

Owners of the new iPhone -- dubbed "iPhone 5" by most -- and those who upgrade older models to iOS 6, can instead download and install the YouTube app that hit the App Store Tuesday.

"The new app is built by YouTube engineers, to give our iPhone and iPod touch users the best mobile experience," said Andrey Doronichev, head of YouTube mobile, in a blog post today.

That was a shot at Apple, which has been criticized for not keeping its own baked-in YouTube app up to date.

The app, which weighs in a 7.5MB and requires iOS 4.3 or later, works on both the iPhone and iPad. Doronichev said that work had begun on a native iPad edition, but other than saying it would launch "in the coming months," did not set a release timetable.

Google touted several new features in the YouTube app, including a new channel guide and several sharing options ranging from Facebook and Google+ to Twitter. The company also claimed that its own app's search tool found videos faster than the Apple-coded versions and that iOS users would have access to more video content, including "official music videos." Google did not mention, however, that it was able to offer music videos because its own app displays advertisements.

Apple's YouTube app did not show ads.

In an email today, a Google spokesman claimed that 25% of the video service's daily views were from mobile devices, but did not spell out how important iOS users were to that traffic. Most measurements still give iOS a large lead in mobile video viewing over Google's own Android.

The ditching of YouTube was the second departure of a major Google-based component from Apple's iPhone. Apple will also replace Google Maps with its own mapping technology in iOS 6.

Apple and Google were once close collaborators. Eric Schmidt, at the time Google's CEO, joined Apple's then-CEO Steve Jobs on stage at the iPhone's 2007 introduction, and served on Apple's board until 2009. Now, they are fierce competitors that have faced off in court, including a patent infringement case where Apple won a major verdict over Samsung, the biggest seller of Android-based smartphones.

The YouTube app will not be removed from iOS 5. Current iPhone and iPad owners who choose not to upgrade to iOS 6, or who cannot do so because of hardware requirements, will be able to continue watching the videos through Apple's app. They can also download Google's and have both on their devices.

Apple is hosting its San Francisco event tomorrow starting at 10 a.m. PT.